The number of cases of AIDS continues to grow and spread to heterosexual populations including infants and children. The majority of pediatric patients who are infected with the AIDS associated retrovirus (ARV) acquire the infection in utero from IV drug abusing mothers. The goal of this project is to characterize the earliest immunologic and neurologic manifestations of ARV infection in a closely followed group of infants and children of IV drug abusing mothers. Our specific aims are: 1) to diagnose ARV infection in fetuses and newborns at high risk for AIDS secondary to maternal intravenous drug abuse, and identify early prognostic markers of disease progressiona and 2) to investigate the early developmental and neurologic consequences of ARV infection in children born to IV drug abusers. To achieve these aims we will study the following groups of subjects: infants of drug abusing women who have antibody to ARV; infants of drug abusing women who are antibody negative and matched to group 1 mothers for age, drug use and intent to breast feed; children of women in either group 1 or group 2 who were born after 1978; and normal children who are having bloods drawn for well child care. We will use very sensitive and specific techniques for detecting virus in blood lymphocytes. The immunologic evaluation will use limiting dilution assays to quantitate the frequency of responding purified T-cells to OKT3 and mitogen and the frequency of interleukin-2 producing T4 and T8 cells and the frequency of responding T4 and T8. We will also measure an early marker of B-cell dysfunction and will assess monocyte status by measuring Dr expression and antigen processing. We have designed a detailed program for neurodevelopmental testing to detect subtle changes in the central nervous system associated with ARV infection. These studies will characterize ARV infection in children of drug abusing women and will provide the basis for developing and testing specific therapeutic interventions.